Sorry, no pictures. It was away before I could get the camera on it.
Earlier today, I saw a bird fly low over a field and vanish over the wall. My first impression from size and style of flight was Sparrowhawk (especially as I've seen one over this field a couple of times), but then I realised it had a forked tail - somewhat like an overgrown House Martin in shape. Colour seemed to be fairly uniform brown, but the light wasn't great, and I only saw it for a few seconds.
Any ideas? Too small, wrong colour and wrong area to be Red Kite.